Carb swap (30 DHTA to 34 DAT) questions

[tomnj]

Just got a new 34 DAT carb for my 1.5, swapping out the original DHTA. have the following questions:

Throttle linkage - the ball mount doesn't exist on the DAT, just a hole where I assume I could mount one. I'm thinking I need to unbolt the linkage arm from the original carb an put on the DAT. Is that right?

Base Gasket - the 34 DAT didn't come with a base gasket, so at first I thought I'd just buy a new one. Well, Midwest bayless sells them, but mention they are supposed to go below the "Bakelite plate". As you can see from the photos, there is no Bakelite plate on the 34 DAT, so what do I do? I'm thinking I need to remove the old gasket and plate from the old carb..but it appears pressed on, should I try to drill it off?

Water Choke - as you can see from the pictures, the old carb has 2 connections on the water choke and the new carb has 3. Should I block off one of the connections on the new carb or maybe switch the choke cover with inputs from the old carb?

 

[roadster27]

Swap over the linkages

What I did when I fitted a DATRA to my car was that I swapped over the linkage pieces, and the housing for the water choke. It fits fine with no modification needed.

I retained the bakelite piece and added new gaskets top and bottom. Honestly I can't remember if I had to enlarge the two holes or not. I did, however, have to drill a hole on the linkage side as my DATRA had a part of the linkage that was hitting the bakelite. I marked it and drilled a 1/4 inch hole and then I had full movement of the linkage.

Not sure how much difference you'll see in performance until you make other changes to the internals and exhaust.

-Dean

 

[tomnj]

The Bakelite plate is a completely different size on the bottom so the holes for the barrels would need to be enlarged, another time consuming job. I would rather buy a new plate already made up for this size carb, if one exists.

I am doing other mods, including exhaust.

 

[tomnj]

I just pulled the platic cover off the throttle linkage which revealed a mounting point for the throttle linkage ball and spring.

Now my question is, do I hook the throttle spring to the hole in the linkage and attach a ball connector to the end part?

Is this the ball piece I need?

 

[Lambertta X1/9]

34 DAT conversion

I did the same conversion last fall. I just used the throttle linkage that was already there. I did however have to shorten the the linkage rod a bit. I did this cutting about 2mm off each threaded side. I believe I also had to accentuate the bend in the linkage a bit to make it line up.

My 34 DAT only had 2 connections for the water choke.

I did enlarge the holes in the bakelite base plate, this was actually quite easy and quick (although dusty). I just traced the gasket holes on the base plate and used a dremel tool with a medium sanding drum to enlarge the holes.

Michael

 

[tomnj]

You guys are right, I was able to pry off the throttle linkage from the old carb and attach to the new one. I called Midwest bayless and they had a Bakelite plate (which includes gaskets) for this carb, so I bought that. I guess I will just block off one of the water choke ports, I don't want to use the old one and mess with the setting.

 

[roadster27]

It's up to you, but it's a straight forward swap

The choke setting thing really isn't that big of a deal. There are marks on the choke, and on the water housing. It's pretty easy.

Personally I hate having plugged off stuff hanging about in the engine bay.

-Dean

 

[EricH]

I called Midwest bayless and they had a Bakelite plate (which includes gaskets) for this carb, so I bought that.

Hmmm... If I had known that I might not have dremeled the plate for a 32 DATRA:sigh: But it' wasn't a lot of work

The plate on your old carb will come off, it's just stuck on (or glued down with sealant if some PO has been truly evil).

You may want to take a little bit of metal off the inside of the intake manifold at the back as well, if that part is intruding into the space below the slightly wider barrel.